How to stretch or compress a spiral cylinder
I would try it with 2 shapekeys:


In the Properties panel > Data > Shapekeys, create 2 shapekeys, keep the second selected.
Go in Edit mode, enable the Proportional Editing mode, Linear option, select the top vertices of your object, adjust the influence circle, pull up so that your object looks like your second image.
Back in Object mode, play with the shapekey Value, push it up to 1 if you want the object to be fully spread.
You might need to make some vertices adjustments for one or the other shapekey in Edit mode, in that case deactivate the Proportional Editing.